My Social Security number is secret.

My card warns me to guard it.

"Keep this in a safe place to prevent loss or theft."

I've done that, for 50 years.

Now I have to share the number with strangers or be denied health care. Medicare says so.

That stinks, I think, and it's stupid.

My opinion, however, does not count.

I know. I've asked.

I've called agencies in question.

I've written to my congressman.

I've gnashed my teeth.

So what.

The government is apparently wed to the absurd tradition of printing Social Security numbers on Medicare cards with an A appended - a stealth move, I suppose, meant to throw off detection.

Could anything be more inane in this age rife with identity theft? For decades I've sheltered my number from healthcare providers, from poll workers and job applications, from stores, even those offering huge discounts in return for store credit accounts requiring a Social Security number. Nope, nope and nope, I've said. Nope.

None of this matters. My number will soon become my ticket to everything from flu shots to life-saving emergency intervention.

Meanwhile other entities, including private insurance providers and the Department of Veterans Affairs, have removed Social Security numbers from ID cards. They see a problem with forcing widespread disclosure of an identifier that links predators to intimate matters, namely finances.

Not Medicare.

This agency merrily toots along, despite dire warnings this year by Patrick P. O'Carroll Jr., inspector general of Social Security. He called for immediate changes.

"Displaying such information on Medicare cards unnecessarily places millions of individuals at risk for identity theft," O'Carroll said, as reported by the New York Times. "We do not believe a federal agency should place more value on convenience than the security of its beneficiaries' personal information."

Nine million cases of identity theft from all sources were estimated for last year. Were any related to Medicare? Who knows for sure.

Sen. Chuck Schumer of New York is behind a bill to force Medicare to issue cards without the Social Security number. You might contact your own council on aging and your legislators to encourage action.

Supposedly Medicare is floored by the idea of spending millions of dollars and several years to transform existing cards to a safer format for the 40 million people carrying these cards.

Perhaps when Medicare's management reaches age 65 things will change.

Social Security numbers are "linked to vast amounts of personal information," O'Carroll noted in his report. "Many individuals carry their Medicare cards in their wallets or purses and could become victims of identity theft should dishonest individuals steal such items or lift their Medicare number from a beneficiary card or medical document."

I've gotten too accustomed to guarding my Social Security number to give it up easily now. So I've made a copy of my Medicare card, blacked out all but the last four digits and will carry this with me.

I cannot advise you to do the same. This may be illegal, certainly inadvisable -it may make you ineligible for care if you suddenly need it.

But if Medicare isn't going to look out for my welfare, I guess I'll have to take a stand on my own behalf.

BETSY SHEA-TAYLOR, a former editor and writer for The Sun Chronicle, is a freelancer.