WASHINGTON — Question: My son-in-law has several medical bills that have gone unpaid due to lack of funds. Are medical bills treated the same as outstanding credit-card debt and does it affect a FICO score?

WASHINGTON — Question: My son-in-law has several medical bills that have gone unpaid due to lack of funds. Are medical bills treated the same as outstanding credit-card debt and does it affect a FICO score?

Answer: Medical bills are not treated the same as outstanding credit-card debt. Consequently, they don't always have a direct effect on your FICO score.

One of the most important factors considered by the FICO algorithms is your revolving-credit utilization ratio. The utilization ratio is calculated as the proportion of your credit-card balances to your credit limits. The higher the ratio, the closer you are to being "maxed out" on your credit cards.

But in the eyes of the FICO score, the lower the utilization ratio, the better. The good news, at least for folks like your son-in-law who are behind in their doctors' bills, is that those payments are not factored into the utilization ratio, says Ethan Dornhelm, a senior scientist at the Fair Isaac Corp.

It's also important to note that not all medical debts are reported to credit bureaus. If the medical debt has gone unpaid long enough for the bill to be have been sent to a collection agency for recovery, then the debt is more likely to be reported to credit bureaus. At that point, according to Dornhelm, it will be posted to the area of the credit report that identifies accounts that have been sent for collection.

"Research has shown that consumers with previous late payments are much more likely to miss payments in the future and as such the FICO score penalizes consumers based on how many late payments and collections they have on file and how recently they occurred," the FICO scientist reports. "The precise impact to the FICO score will depend on the other info contained in the credit file."