Getting Disability Benefits for Undifferentiated or Mixed Connective Tissue Disease

Connective tissue—such as bone, cartilage, and fat—makes up the support structure for all other tissues and organs in your body. When these tissues become inflamed, they can harm the parts of the body that they're connected to. Doctors refer to this state as "connective tissue disease," which includes disorders like rheumatoid arthritis, scleroderma, and lupus.

Undifferentiated connective tissue disease (UCTD) and mixed connective tissue disease (MCTD) are terms used to describe autoimmune disorders that target connective tissue. These disorders can cause stiff, painful joints that may interfere with the ability to complete job duties. If your symptoms are severe enough to keep you from working full-time for at least one year, you might qualify for Social Security disability benefits.

What's the Difference Between Undifferentiated and Mixed Connective Tissue Disease?

"Undifferentiated connective tissue disease" is sometimes used interchangeably with "mixed connective tissue disease" because the symptoms manifest in similar ways. Generally speaking, UCTD means that you display some features of multiple autoimmune diseases but don't meet the diagnostic criteria for any specific disorder, while MCTD means that you have overlapping symptoms with at least two diagnosable disorders.

Currently, researchers aren't certain what causes UCTD or MCTD, but it's thought to be a combination of genetic and environmental factors. Having a family history of connective tissue or other autoimmune diseases, being exposed to toxins, or fighting off infections might contribute to the development of the disorders.

Diagnosing and Treating Symptoms of MCTD

MCTD is associated with a high amount of an antibody called "ribonucleoprotein", so your doctor may make the diagnosis after reviewing the results of a blood test. Some additional factors can point to mixed connective tissue disorder rather than a single connective tissue disorder (like lupus or scleroderma) such as the presence of Raynaud's phenomenon, severe arthritis, or a lack of the kidney problems frequently associated with lupus.

Patients with MCTD may also meet the diagnostic criteria for several other connective tissue diseases, like Sjogren's syndrome, polymyositis, or Marfan syndrome. Common symptoms of these disorders include:

• fatigue
• swollen or stiff fingers
• muscle and joint pain
• difficulty swallowing, and
• pulmonary hypertension.

Even though symptoms of MCTD overlap with those of other well-defined connective tissue diseases (MCTD is sometimes referred to as an "overlap syndrome" because of it), the symptoms of these diseases don't appear all at once. Rather, they can pop up over the course of several years. While MCTD is an uncommon disorder, it is more prevalent in women younger than 50. Treatment usually involves corticosteroids, calcium channel blockers, or other immunosuppressant medications.

Diagnosing and Treating Symptoms of UCTD

Undifferentiated connective tissue disease can have similar symptoms to mixed connective tissue disease, with the main difference being that UCTD symptoms don't meet enough criteria to be diagnosed as another kind of connective tissue disease. Common UCTD symptoms include:

• skin rashes
• joint pain and swelling
• eye inflammation (conjunctivitis), and
• muscle weakness, tenderness, or atrophy.

Women younger than 45 make up the vast majority of all UCTD cases. These cases usually don't progress into a "full-blown" connective tissue disease, especially if they haven't done so after five years. Up to 60% of cases remain undifferentiated, and up to 20% have their symptoms completely subside. As with MCTD, treatment for UCTD typically involves symptom management with anti-inflammatory medications.

Does Undifferentiated or Mixed Connective Tissue Disorder Qualify for Disability?

Simply having a diagnosis of MCTD or UCTD isn't enough to get disability benefits. You'll need to have evidence in your medical records demonstrating that your symptoms prevent you from engaging in substantial gainful activity for at least twelve months. You can do this in one of two ways—by meeting the requirements of a medical listing or by having functional limitations that rule out all full-time work.

Getting Disability by Meeting the Listing for UCTD and MCTD

Social Security uses a medical handbook (the "Blue Book") that outlines the evidence needed to establish disability automatically for certain illnesses the agency considers especially severe. Social Security calls these rules "listings." If your doctor's notes contain the information required by a specific listing, you can qualify for disability without having to prove that you can't do any jobs.

Disability claims for undifferentiated or mixed connective tissue disease can be evaluated under listing 14.06 in the section for immune system disorders. In order to get disability by "meeting the listing," you'll need to first show that you have an autoimmune syndrome that doesn't satisfy the diagnostic criteria of another specific disorder. You'll then need to show that the UCTD or MCTD causes either one of the following sets of symptoms:

• At least two of your organs or body symptoms are affected by the disease, with one of the organs or systems affected to at least a "moderate" degree of severity, and you display at least two of the constitutional signs or symptoms (severe fatigue, fever, malaise, or involuntary weight loss) of the disease.
• You have "repeated manifestations" of UCTD or MCTD, with at least two of the constitutional signs or symptoms, and you have "marked" limitations in at least one of three functional areas (managing daily activities, social functioning, and completing tasks on time).

Social Security considers "repeated manifestations" to mean flare-ups that occur on average three times per year, with each episode lasting two weeks or more. But you can still qualify if you have fewer (but much longer) or shorter (but much more frequent) flare-ups as well, as long as they result in at least one marked limitation in an important functional area. "Marked" limitations are in areas where your UCTD or MCTD "seriously interferes with your ability to function". For example, you may have a marked limitation in social functioning if you can't physically sit through a movie or dinner with your friends due to your connective tissue disease.

Getting Disability Because You Can't Work Due to MCTD or UCTD

You can still get disability benefits even when you don't meet a listing if you can show that symptoms from your medical conditions keep you from performing any full-time jobs. (This is actually the most common reason why Social Security approves disability claims.) In order to determine what, if any, kind of work you can do, the agency will first need to assess your residual functional capacity, or "RFC". Your RFC is a set of restrictions that reflect the most you're still able to do, physically and mentally, in a work environment.

Social Security reviews your medical records and self-reported activities of daily living for evidence of limitations that could affect your job performance. For example, you might not be able to do work where you'd be on your feet all day because your joints are too painful or swollen. Likewise, numbness in your hands or shoulders could keep you from jobs involving frequent typing or lifting heavy objects. Here's an example of what an RFC might look like for somebody with undifferentiated or mixed connective tissue disease:

Somebody with an RFC like the one in the above example will likely be awarded disability benefits because they wouldn't be able to perform most of the physical requirements of even sit-down work. Not everybody will have such extreme limitations, however. If you can return to your past jobs or make a transition to other, less strenuous work, Social Security can't find you disabled.

The more severe your symptoms are, the more limitations you'll have in your RFC, and the more likely it is that you won't be able to do any job. That's why getting your symptoms documented in your medical record is so important. Any limitations that are in your medical record but aren't included in your RFC can form the basis of a successful appeal if you're denied.

Medical Evidence You'll Need to Get Disability for MCTD or UCTD

Your medical records are the foundation of your disability claim. Social Security will need to see clinical evidence of a medically determinable impairment, not just subjective statements about fatigue or feeling unwell. Ideally, to get approved for disability for mixed of undifferentiated connective tissue disease, your medical records will contain the following:

• a diagnosis of UCTD or MCTD by a rheumatologist (a doctor that specializes in immune system disorders and inflammatory diseases)
• blood tests confirming the presence of antinuclear antibodies or a positive rheumatoid factor, indicating that you have an autoimmune condition
• medical imaging, such as a CT scan, X-ray, or MRI showing joint or organ damage
• your doctor's clinical notes containing observations found on physical examination, and
• a history of any medications you've tried and whether they helped or caused side effects.

Social Security might also send you for a consultative exam if the agency thinks more information is needed in order to make a disability determination. You can also ask your doctor to write a medical source statement that may persuade Social Security to award you benefits, provided the doctor's opinion isn't contradicted by your record as a whole.

Disability Benefit Amounts for MCTD or UCTD

Social Security doesn't award disability benefits based on the specific medical diagnosis you've received or the types of limitations keeping you from working. Instead, the amount of money you'll receive depends on the type of disability program you're eligible to receive payments from.

Everybody who is approved for Social Security Disability Insurance, or SSDI, receives a monthly benefit that's calculated based on their employment record ("work credits"). And everybody who is approved for Supplemental Security Income (SSI) receives an amount equal to the federal benefit rate minus any countable income they have in that month.

The exact numbers used to calculate SSDI and SSI change each year to account for increases in the cost of living. For 2025, the federal benefit rate for SSI is $967 per month, although many states provide a modest supplemental amount in addition to the federal baseline. SSDI benefits max out at $4,018 per month, but the average amount is much less, at $1,580. That's because part of the SSDI calculation is based on how much you've earned before you became disabled, which varies widely between beneficiaries.

How to Apply for Social Security Disability Benefits and What to Do If You Don't Qualify At First

An easy way to file for Social Security disability benefits is by using Social Security's online web portal. You can also file a claim over the phone by calling the national disability hotline at 800-772-1213 (TTY 800-325-0078) between 8 a.m. and 7 p.m., Monday through Friday. If you'd prefer to apply in person, you can make an appointment at your nearest Social Security field office.

Keep in mind that most disability claims aren't approved on the first try ("initial determination"). There are several reasons why your disability application may be denied. You might not meet the financial eligibility criteria for either SSDI or SSI, or your limitations weren't considered severe enough to keep you from returning to your past relevant work.

There isn't much you can do if you don't meet the preliminary legal requirements for receiving Social Security benefits, but the agency can make mistakes when determining technical eligibility, so you should double-check with an agency representative. However, if you were denied because Social Security thought you could return to your past work or have transferable skills that you could use in other jobs, you may want to consider consulting an experienced disability lawyer to get a sense of how strong a possible appeal would be.